CONTINUOUS AUTOMATED MEASUREMENT OF THE SOLUBLE FRACTION OF ATMOSPHERIC PARTICULATE MATTER

A new approach is introduced for the quantitative collection of aerosol particles to submicrometer size, The design and construction of a continuously operating system is described, Particles are continuously transferred to a liquid stream utilizing condensation of supersaturated vapor to promote particle growth followed by collection that relies on impaction and the thermophoretic effect. The automated system is simple to construct and operate and provides quantitative collection of aerosol particular matter even at a flow rate of 10 L/min. Individual measurements of aerosol particles and soluble gases are achieved by combining the system with a wetted wall parallel plate diffusion denuder, Interfaced to an inexpensive ion chromatograph for downstream analysis, the detection limits of the overall system for particulate sulfate, nitrite, and nitrate are 2.2, 0.6, and 5.1 ng/m(3), respectively, for a 8 min sample. The system has been used for the field measurement of gaseous and particulate components; results are presented.